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GHSA-fg47-3c2x-m2wr

CriticalCVSS 10 / 10
Published Aug 30, 2021·Last modified Mar 13, 2026
Affected Components(0)

No affected components available

Description

Impact

A vulnerability in TimelockController allowed an actor with the executor role to take immediate control of the timelock, by resetting the delay to 0 and escalating privileges, thus gaining unrestricted access to assets held in the contract. Instances with the executor role set to "open" allow anyone to use the executor role, thus leaving the timelock at risk of being taken over by an attacker.

Patches

A fix is included in the following releases of @openzeppelin/contracts and @openzeppelin/contracts-upgradeable:

  • 4.3.1
  • 3.4.2
  • 3.4.2-solc-0.7

Deployed instances of TimelockController should be replaced with a fixed version by migrating all assets, ownership, and roles.

Workarounds

Revoke the executor role from accounts not strictly under the team's control. We recommend revoking all executors that are not also proposers. When applying this mitigation, ensure there is at least one proposer and executor remaining.

References

Post-mortem.

Credits

The issue was identified by an anonymous white hat hacker through Immunefi.

For more information

If you have any questions or comments about this advisory, or need assistance executing the mitigation, email us at security@openzeppelin.com.

Risk Scores
Base Score
10.0

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability. The vulnerability can affect other systems as well, not just the initial system. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data. There is a high impact on the availability of the system.

Threat Intelligence
9.1

Active exploitation in the wild has been confirmed. Immediate patching or mitigation is required.

EPSS
N/A

Probability that this vulnerability will be exploited in the wild within the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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